He will then travel to Belgium, where he will meet Thursday with NATO and European Union officials to discuss the possibility of cooperative post-war reconstruction and security in Iraq.
It is the first overseas trip for a top Bush administration official since the war in Iraq began on March 20.
In Ankara, Powell will meet with Turkish Prime Minister Recip Tayyip Erdogan to discuss the progress of the war in Iraq and post-war reconstruction in the region. He will also ask Turkey not to send their troops into northern Iraq.
"I want to reassure Turkish leaders that we believe the work we are doing there should make it unnecessary for them to consider any incursions," Powell said Monday. "The United States wants to make sure we have a common understanding."
U.S. presidential envoy Zalmay Khalilzad has been in Ankara and northern Iraq over the last week, working with Turkey to gain a commitment not to send troops into the neighboring country.
In an editorial in the Wall Street Journal's European edition Monday, Turkish President Erdogan said Turkey would not send troops into Iraq unilaterally, but that Turkey must retain the right to self-defense in the case of a "terrorist infiltration."
Turkish leaders have also said an influx of Iraqi refugees or a Kurdish attack on the oil-rich city of Kirkuk in northern Iraq could trigger a Turkish invasion.
Also Tuesday, Iraqi Foreign Minister Naji Sabri appealed to Turkey, imploring their neighbor to help them fight U.S. and British forces.
"The United States is trying to drag the neighborly, friendly and Muslim Turkish people into a war that will lead to only Allah knows where," Sabri said in an interview in Baghdad with Turkey's state-run Anatolian news agency.
While in Brussels, Powell will meet with NATO and European Union officials at NATO headquarters. Reijo Kempinnen, a spokesman for the European Union's Executive Commission, confirmed the secretary will meet with Greek Foreign Minister Georges Papandreou, European Union foreign policy chief Javier Solana and the EU Commissioner for External Affairs Chris Patten. He will also meet with Russian Foreign Minister Igor Ivanov.
EU officials told Powell he should not expect any definite decisions from his sudden trip, and the announcement of his trip received mixed reaction. The Greek government, which currently holds presidency of the European Union, hinted that the secretary of state's trip was overdue.
"We are not opposed to these meetings. But it would have been good if Mr. Powell had taken such initiatives before the start of the war," said Greece's government spokesman Christos Protopapas.
"But any discussions are welcome. We are not against any dialogue. It's never too late," he told reporters in Athens.